Experimental Behavior of Hollow Non-Prismatic Reinforced Concrete Beams Retrofit With CFRP Sheets

Abstract

This study deal with five reinforced concrete non-prismatic beams hollows section retrofit with carbon fiber reinforced polymer (CFRP) under two-point loads. These beams of dimension (length 1170 x height 260 x width 150mm) with different sections (i.e. solid or hollow of two shapes) are investigated to evaluate the behavior at the experimental test and to get the capacity of beams retrofit with CFRP that is similar to the capacity of solid sections. The end support to provide all beams as simply supported. The four R.C. beams are retrofitted with CFRP strip (Sika CarboDurS512) and designed to test up to failure. Also, it's have been explaining the effect of Parameters which includes the effect of section (solid or hollow), hollow opening (shapes and materials), and effect of retrofitting with CFRP. Non-prismatic beam with recess along length compared with non-prismatic solid beam results show a decrease in stiffness and an increase in the beam deflection by about (53% and 40% respectively). The square hollows are provided by steel pipe led to an increase in load capacity and a decrease in the corresponding deflection compared with other materials (i.e PVC) by about (56%, and 33%), also the retrofit of beams by CFRP contributed to again in load capacity by about (27%). Finally, the comparisons between all beams are based on load carrying capacity, deflection, crack pattern, the strain of concrete, and mode of failure.